1. Field of the Invention
The present invention relates to a liquid droplet ejecting device, an inkjet recording apparatus, a liquid droplet ejecting method, and a storage medium for liquid droplet ejecting method.
2. Description of the Related Art
Inkjet recording apparatuses usually have been known as image recording apparatuses or image forming apparatuses such as printers, facsimile machines, copiers, etc. In the inkjet recording apparatus, an inkjet recording head, which includes nozzles to eject ink droplets, pressure chambers communicating with the nozzles, and piezoelectric elements to pressurize the ink in the pressure chambers, form desired characters and figures on recording media (paper, metal, wood, and ceramics).
The reason why an abnormal image is formed on the recording medium is abnormal ejection (ink droplet is not normally ejected from the nozzle) caused by a state in which air bubble(s) is mixed in the pressure chamber, a state in which foreign objects (paper powder, liquid pool) are attached to the nozzle, and a state in which ink is thickened (ink viscosity is increased).
As one known inkjet recording apparatus (JP2004-276273), when there is a residual vibration after the ink droplet is ejected, by using an oscillation circuit, a F/V conversion circuit, a waveform shaping circuit, a comparator circuit, a filter circuit, etc., the abnormal ejection is detected based on the frequency change and/or amplitude change.
However, in the conventional inkjet recording apparatus, a complex circuit is required for detecting the abnormal ejections, such a configuration causes circuit size to be greater and the circuit to become costly.